Saw blade



April 1,1930. E. A. BOLINDER 1,752,586

SAW BLADE Filed Oct. 8, 1928 @g Mn/w Patented Apr. 1, 1930 UNITED STATESPATENT OFFICE When sawing timber to form boards and battens it is ofgreat importance for economic purposes that the loss through cutting beas small as possible, and inasmuch as the loss is directly dependent onthe thic ness of the blade and also on the setting of the teeth of thesaw, it is desirable to use very thin saw blades with a minimum amountof setting. Hitherto, this could not be accomplished satisfactorily forthe reason that when a thin blade with a small setting was used thesetting was not permanent owing to the fact that the thin bladed teethcould not be given the rigidity required to maintain the setting whenthe teeth were subjected to lateral strains during sawing. In suchcircumstances the benefit of the thin blade was nullified.

The present invention has been made with the above-mentioned experiencein mind, and the invention provides for such an arrangement that the sawblade may be made exceedingly thin and still so rigid in its entiretythat the setting of the blade teeth will be permanent even if thesetting is made as slight as possible. As has been shown by experience,facilities are thus provided for sawing with very thin cuts, that is tosay with a very small cut loss. The problem is thus solved in asatisfactory and, for practical applications, advantageous manner.

he arrangement provided according to the invention is principallycharacterized by the saw blade being provided with corrugationsextending obliquely over the same, said corrugations having such aposition and such an extension relatively to the blade teeth that one ormore of the corrugations will extend along the lateral surface of eachtooth and, furthermore, in such a manner that one of the corrugations atleast will terminate at the fore edge of the tooth or in or near thepoint of the tooth, said corrugation then imparting to the pointedportion of the tooth, the rigidness required to maintainthe settin 'l hearrangement thus provided according to the invention entails a furtheradvantage of the greatest importance, involving that the thin saw bladewhen stretched in a blade stretchint QF STQCKHOLM, SWEDEN LADE 311,207,and in Sweden February25, 192 8.

frame, obtains the requisite rigidness against bending strains bothlaterally and longitudi nally, that is to say in the direction of the ofthe blade, and also in a direction at right angles thereto.

The accompanying drawing illustrates an embodiment of'the inventiomandshows a portion of a saw blade viewed in elevation with a part brokenaway so as to show a cross section;

'According to the invention, 1 designates the fore edge, 2 the point, 6the outer edge, and 3 the rear edge of each blade tooth. "According tothe example shown, each tooth coincides with two blade corrugations 4iand 5 rranged according to-the invention, said corrugations extendingobliquely overthe blade and parallel with each other and, preferably,also parallel to the rear edge 30f the tooth. The front corrugation aterminates at the fore edge 1 of the tooth and at or in the proximityofthe tooth point 2. -The rear corrugation 5 terminates intheoutwardly:directed edge 6 of the tooth and coincides, orapproximately coincides with the rear tooth edge 3.

The corrugations thus provided are arranged at each other tooth in sucha manner as to form elevations on the one side of the saw blade, whereasat the adjacent tooth they form elevations on the opposite side of theblade.

The setting is effected with the tooth points deviating toward that sideof the blade on which the respective corrugations form elevations, andfrom the statements hereinbe'fore as well as from the drawing it will bereadily understood that the corrugations will then offer a greatresistance to the active lateral pressure on the teeth in the sawingoperation, so that the setting, despite the extreme thinness of theblade, will nevertheless be maintained in a safe manner.

lVith the blade stretched tightly in the blade frame, the corrugationswill also prevent bending of the blade either along the blade or in thetransverse direction thereto.

By adapting the depth of the corrugations so that they will only be afraction or" the blade thickness, for instance thereof, there willremain, according to this example, 1

of the blade thickness inside the bottoms of the corrugations, wherebythe blade may be subjected to a powerful tensile stress, without thecorrugations thereof being deformed in consequence of the strain.

\Vhat I claim is 1. In a saw, a blade provided with oorru gationsextending across the blade throughout the width thereof, at least two ofsuch corrugations extending to the lateral surfaces of each tooth of theblade between the point of the tooth and the rear edge thereof, so thatthe corrugations will impart to each tooth a rigidness laterally thateven with thin saw blades the setting of the teeth will remain againstthe influence of lateral pressure acting 011 the teeth.

2. A saw blade as claimed in claim 1, characterisccd by the fact thattwo adjacent and mutually parallel corrugations coincide with eachtooth, one of which corrugations teriuinating at the fore edge of thetooth and in the vicinity of the point of the tooth, and the other ofsaid corrugations terminating at the olltwardly directed edge of thetooth and substantially coinciding with the rear edge of the tooth.

3. A saw blade arranged according to claim 1, characterized by the depthof the corrugations being only a fraction, for instance of the bladethickness, so that there will remain of the blade thickness between thebottoms of the corrugations, a portion which is capable of withstandinga powerful tensile strain, without this being imparted onto thecorrugations to deform the same.

In testimony whereof I aliix my signature.

ERIK AUGUST BOLINDER.

